ok,so i have a 99` crown vic p71 w/ 125,000 miles on it and ever since i bought the car there has been a type of"clatter" noise coming from the front end of the motor,recently its been getting louder, and no its not knocking,i did the whole stethiscope with a pipe thing,it purrs like a kitten and its not any of the components(water pump,a/c,alternator),i tried taking the belt off and running it for a few seconds,still does it,i have a hunch its the chain,but im not quite 100 percent sure,if so,what parts exactly do i need?any help would be greatly appreciated,thank you .

yes sir, it's the timing chain tensioner guides that are worn out! You've got to remember that a P71 will have much more internal wear than a civilian crown because the engines run much longer regardless of the miles. I just replaced mine and just in time too. Typically by the time you can clearly hear the rattling, the guides and tensioner guides are shot! You'll need a "timing set" valve cover gaskets, front cover gasket set and go ahead and put a water pump in it while you're in it. I got my timing set on-line it was a hell-of-a-lot cheaper. Cloyes set from "Rock Auto".

thanks so much,i wasn`t quite sure,but i knew someone on here could help,umm about the valve cover gaskets,should i replace them if they arent leaking(cause they look like they were replaced once already),from the looks of it,the chain cover doent come close to the valve covers,hmmmm,il take your word for it and get a timing set,anyways thanks

What's the normal service life for timing chains under normal use? I have about 225k on my GM. I hear what sounds like pre-ignition ping sometimes during hard acceleration. Could this be the chain against the cover?